Fluid media intended, for example, for therapeutic purposes or other purposes must often be freshly prepared close to the time they are actually to be used, because only the components forming the medium are inherently stable and/or storable enough. The ultimately prepared medium may not be inherently stable or storable enough. In practical applications, it is often necessary to store a dry substance and a fluid separately from one another until the use of the medium formed from a mixture of the dry substance and the fluid is imminent.
Generally the procedure followed involves taking the fluid, for example, a solvent, by a hypodermic needle and injecting it into a container containing the dry substance. Afterwards the resulting solution is removed with a new syringe to be applied or administered in the desired manner. In therapeutic applications, this administration can take place, for example, by injection, placement as an additive in an infusion container or the like.
Such application processes, in which injection needles are used, entail the risk that injuries can occur. This circumstance is extremely problematical when working in an environment in which the presence of HIV viruses can be expected.